"Naren has been working on a port of Android 4.0 to Raspberry Pi, and as you can see from the screenshots and video below, he's been making great progress. Hardware-accelerated graphics and video have been up and running smoothly for some time; AudioFlinger support is the only major missing piece at the moment." Not sure how useful it is, but still pretty cool.

Assuming the customer is ok with the available licenses, open source is usually chosen to lower project costs, not because of quality nor to contribute anything back.

Dead on. Cost is certainly the biggest factor (taking into account all costs, of course, not just licensing). That doesn't mean those companies won't contribute back to the community, but it's not a priority, nor something they'll do if it costs them too much.